Benzodiazepine receptor GABA ratios: regional differences in rat brain and modulation by adrenalectomy

GABA ratios were measured in several brain regions in sham-operated, adrenalectomized and adrenalectomized dexamethasone-injected rats. In sham-operated animals, GABA ratios varied 2.5-fold among the regions. In adrenalectomized animals the GABA ratios were increased in the hypothalamus and striatum but decreased in the hippocampus. Dexamethasone injection into adrenalectomized animals reversed the increased GABA ratio in the striatum. These data indicate that glucocorticoids can modulate GABA ratios, possibly by affecting the availability of the individual receptors in the receptor complex.